The present invention is directed towards a plug for a circular article. More particularly, the present invention is directed towards a dust plug for a fluid conduit system.
It is known in the fitting/coupling art to use dust plugs with fluid conduit systems, e.g. hoses, threaded pipes, that have been provided with a coupling. The dust plug is inserted into the end of the system, mating with the coupling, to prevent any loss of material from the system and to prevent the introduction of foreign material into the system. A conventional dust plug for a cam and groove fitting is illustrated in FIG. 5. The plug 100 has a central body 110 with a hollow center 112. One end of the plug 114 has a tapered end 116 to facilitate insertion of the dust plug 100 into the hose. Along the length of the central body 110 is a groove 118 that cooperates with a lever arm of a cam and groove coupling. The other end of the dust plug 100 has a tab 120. The tab 120 has an aperture 122 for inserting a chain. Typically, a chain is inserted into the tab 120 in order to mate the plug 100 with the system so that the plug 100 is not lost when not inserted into a coupling. However, since the tab 120 is the only portion of the plug 100 that is graspable once the plug 100 is inserted into a coupling, operators have tended to use the tab 120 as the removal means for the plug 100, either by directly pulling on the tab 120 or pulling the chain threaded through the tab 120.
The dust plug 100 is inserted into a coupling so that the end 114 is inserted into the fluid conduit system while only the tab removal means 120 extends outside of the coupling and hose end. The hollow center 112 communicates with the interior of the system and any material that may flow through the system. To remove the dust plug 100 from the hose, after releasing the lever arm of the cam and groove fitting, the operator typically pulls any chain mounted through the aperture 122.
However, this dust plug 100 has several design limitations. Because the axial end 114 is a tapered ring of metal, the end 114 of the dust plug may become easily damaged by dropping the dust plug 100. Since the hollow center 112 of the dust plug 100 communicates with the interior of the fluid conduit system and any material within the system, any dirt or any other foreign objects that enter into the hollow center 112 may enter the system and potentially contaminate the material flowing through the system. The shape of the dust plug 100 makes it difficult and time-consuming for an operator to clean out the hollow center 112 of the dust plug 100 each time the dust plug 100 is inserted into a coupling. Also, the configuration of the removal means 120 is susceptible to being damaged and broken off if the dust plug 100 is dropped or if the operator pulls too hard on any chain threaded through the aperture 122. Once the removal means 120 is broken off, removal of the dust plug 100 becomes extremely difficult for the operator.
The present invention is directed towards a dust plug for insertion into a fitting that overcomes or eliminates the disadvantages of the conventional dust plug. The dust plug is comprised of an insertion end, removal means, and a hollow central body located between the insertion end and the removal means. The plug is characterized by the insertion end being formed as a solid flat end.
Another aspect of the inventive dust plug is that the removal means is formed as a continuous lip about the end of the hollow central body.
In another aspect of the invention, the removal means has a diameter greater than the outer diameter of the hollow central body.
In another aspect of the invention, the plug is further characterized by the plug comprising an intermediate area adjacent the removal means and the hollow central body. The intermediate area may have a diameter less than the outer diameter of the hollow central body. The intermediate area may also be provided with at least one tab formed therein so that a chain may be attached to the plug.